Conventional systems used to crimp or swage work pieces together create ridges, bends and/or non-uniformities. These crimping or swaging devices typically use multiple fingers or jaws that are moved inward towards a common central longitudinal axis in a straight, non-overlapping motion. These jaws commonly have spaces between them that create the ridges, bends, and/or non-uniformities which can be problematic. For example, when the crimping devices are used to clamp air or hydraulic hoses onto fittings, such as hose barbs, the ridges, bends, and/or non-uniformities can become leakage paths for the fluids carried in the hoses.
FIG. 1 illustrates a U-type die typical of a two-part crimper device 10 using so-called “straight, non-overlapping motion”. The two jaws 12 are disposed in relation to each other and are brought together to produce a round (or other shape) crimp when fully closed. It is only in the final position when the jaws 12 are fully brought together that the spaces or gaps 14 are closed and the throat or crimping surface 16 becomes continuous. These non-uniformities in the crimping surface result in non-uniform flow of the swaged material. FIG. 2 illustrates a ferrule 18 that was crimped with such a crimping device 10 and demonstrates the non-uniform “ears” 20 that are formed which can become leakage paths if such a ferule 18 joins a hose to a fitting.
In an attempt to reduce or eliminate these non-uniformities, crimping tool manufacturers have produced systems with a larger number of jaws. FIG. 3 illustrates such a crimping device 22 having six jaws 23 with gaps or spaces 24 therebetween. The jaws 23 are radially moved inward towards a central longitudinal axis to affect a crimp. Although the larger number of jaws 23 produces a more uniform result, FIG. 4 illustrates that a ferrule 25 crimped by this device 22 still demonstrates non-uniformities 26 which can become leakage paths 28 between the hose 30 and the fitting 32. It is noted that it is not possible to produce a fully round, uniform crimp with straight, non-overlapping motion because the spaces 24 between the jaws 23 do not fully constrain the ferrule 25. Similar problems are also created when the crimping devices are used to join other items such as, for example, electrical connectors, stanchions, and the like.
In another attempt to reduce or eliminate these non-uniformities, crimping tool manufacturers have produced systems with a jaws travel along an arc. FIG. 5 illustrates such a crimping device 34 having four jaws 36 having a pivot mechanism such that the jaws 36 each travel along an arc to open and close the throat. The jaws 36 moving along an arc, however, do not remain in contact with each other and thus still can result in nonuniformities. In fact, such crimping devices 34 do not achieve continuous flow because the crimping devices 34 simply smash four arcs of the cylindrical ferrule flat. They do not uniformly reduce the overall perimeter of the ferrule. Such crimping devices 34 also cannot produce round crimps and cannot crimp bulky fittings onto continuous work pieces because the devices are incapable of side entry and exit. Accordingly, there is a need in the art for an improved method and device for crimping or swaging an outer work piece onto an inner work piece.